Browse Prior Art Database

Growth of Smooth Transparent Epitaxial ZnO Layers on Sapphire and Spinel Crystal Substrate

IP.com Disclosure Number: IPCOM000078553D
Original Publication Date: 1973-Jan-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 25K

Publishing Venue

IBM

Related People

Berkenblit, M: AUTHOR [+3]

Abstract

Zinc oxide has application in surface acoustic wave, dielectric and display devices.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 54% of the total text.

Page 1 of 3

Growth of Smooth Transparent Epitaxial ZnO Layers on Sapphire and Spinel Crystal Substrate

Zinc oxide has application in surface acoustic wave, dielectric and display devices.

The following process is described in the IBM Technical Disclosure Bulletin at Vol. 13, No. 11, April 1971, page 3446 and provides for the transport and epitaxial growth of zinc oxide on substrates heteroepitaxially. By using sapphire single-crystal substrates, epitaxial zinc oxide is deposited in accordance with the following reactions:

(Image Omitted)

Experimentally, helium is transpired over a zinc bed at a defined temperature. Simultaneously, helium is transpired over a water source also at a defined temperature. The reactants are then mixed at a reaction site, where either growth is permitted to take place on a substrate (temperature of the reaction site is 700 to 1100C degrees) or, the reaction site is used as the in situ source of zinc oxide (the reverse of reaction (3)) to enforce a hot-to-cold transport, the substrate being positioned in the colder region.

Criticality of growth conditions, in situ pretreatment of the substrates (sapphire and spinel) and the manner in which the substrate is supported during growth, is cut, lapped, mechanically polished, annealed and chemically polished are described herein. 1. In Situ Substrate Treatment.

Treatment of the substrates in ca 5.7 x 10/-2/ atm. of H(2)O in He at 900 degrees C for 1 hour, at 1 l/min had very pronounced effects on deposit transparency and surface smoothness (particularly at low Zn/H(2)O input ratios). For example, in the range of P(Zn)/P(H(2)O = 0.01, deposits without pretreatment invariably exhibited a matte finish at flow rates below 2 l/min and tended to be translucent to opaque. With pretreatment, the deposit quality improved markedly. 2. Growth Conditions.

At a Zn/H(2)O reactor pressure ratio of 0.088 it was found that over a range of total fl...